1. Field of the Invention
The present invention relates generally to a metal processing machine for shearing sheet materials such as sheet metals and more particularly to a notching machine which is a kind of presses for shearing sheet materials to form notches of various shapes on sheet materials.
2. Description of the Prior Art
In many industries, there exists a requirement to form notches of various shapes such as V-shaped configurations at corners and edges of sheet materials such as sheet metals.
Heretofore, it has been usual that notches are formed on sheet materials by presses with use of specially designed shearing tools. Also, there have been shearing presses often referred to as notching machines which have upper and lower shearing tools and are specially designed to form either corner notches or edge notches on sheet materials.
It has been of course desired to form both corner notches and edge notches of various shapes on sheet materials with use of a single notching machine. Also, in order to form notches of various shapes on sheet materials of a variety of thicknesses, it is necessary to adjust the clearance between the upper and lower shearing tools in notching machines according to thickness of sheet materials to be notched.
Heretofore, there has been no notching machines that can form both corner notches and edge notches on sheet materials and are so designed that the clearance between the upper and lower tools can be adjusted according to thickness of sheet materials to be notched. Therefore, in conventional notching machines, shapes of notches that can be made on sheet metals have been limited, or otherwise it has been necessary to often change the upper and lower shearing tools according to thickness of sheet materials to be notched. Accordingly, heretofore, many notching machines and notching tools have been required to form a variety of notches of various shapes on sheet materials of various thicknesses, and therefore much cost has been required.